Reserved Word - Reserved Words and Language Independence

Reserved Words and Language Independence

Microsoft’s .NET Common Language Infrastructure (CLI) specification allows code written in 40+ different programming languages to be combined together into a final product. Because of this, identifier/reserved word collisions can occur when code implemented in one language tries to execute code written in another language. For example, a Visual Basic.NET library may contain a class definition such as:

' Class Definition of This in Visual Basic.NET: Public Class this ' This class does something... End Class

If this is compiled and distributed as part of a toolbox, a C# programmer, wishing to define a variable of type “this” would encounter a problem: 'this' is a reserved word in C#. Thus, the following will not compile in C#:

// Using This Class in C#: this x = new this; // Won't compile!

A similar issue arises when accessing members, overriding virtual methods, and identifying namespaces.

In order to work around this issue, the specification allows the programmer to (in C#) place the at-sign before the identifier which forces it to be considered an identifier rather than a reserved word by the compiler.

// Using This Class in C#: @this x = new @this; // Will compile!

For consistency, this usage is also permitted in non-public settings such as local variables, parameter names, and private members.

Read more about this topic:  Reserved Word

Famous quotes containing the words reserved, words, language and/or independence:

    “This is that which we call Character,—a reserved force which acts directly by presence, and without means.”
    —Ralph Waldo Emerson (1803–1882)

    “There can be no doubt that distrust of words is less harmful than unwarranted trust in them. Besides, to distrust words, and indict them for the horrors that might slumber unobtrusively within them—isn’t this, after all, the true vocation of the intellectual?”
    —Václav Havel (b. 1936)

    “The etymologist finds the deadest word to have been once a brilliant picture. Language is fossil poetry. As the limestone of the continent consists of infinite masses of the shells of animalcules, so language is made up of images or tropes, which now, in their secondary use, have long ceased to remind us of their poetic origin.”
    —Ralph Waldo Emerson (1803–1882)

    “To drive men from independence to live on alms, is itself great cruelty.”
    —Edmund Burke (1729–1797)